There can't be many internet businesses founded in 2000 that thank the dotcom crash for their success. But for Mumsnet, the online community for mothers launched in January of that year, the bursting of the tech bubble was a stroke of good fortune.

"All our business projections went out of the window and the man that was going to invest in us disappeared when crashed," Justine Roberts, Mumsnet co-founder and ceo, told a recent meeting of the Association of Online Publishers.

"And I think that had we raised the money we wanted to raise, there's no question we would have been out of business very quickly because we'd have had fancy offices, plenty of staff and no revenue."

Instead, an infant Mumsnet remained a back-bedroom operation for several years, gradually building a community in a process described by Roberts as "the slowest of slow burns...a classic internet model of low-cost and steady word-of-mouth growth".

Now, 11 years later, Mumsnet attracts 1.5 million unique visitors and 30 million page impressions every month. Of this, 95% of traffic is generated by the site's forums, containing peer-to-peer discussions on all aspects of parenting.

When I spoke to her, it became clear that the respect which Roberts holds for her community members is instrumental to Mumsnet's success.

Justine Roberts talks about the growth of Mumsnet (0:58)

Of the 1 million regular visitors who think of themselves as "Mumsnetters", 20% use the site more than 20 times per month, 90% are aged 25-45, 75% have a university degree, 70% are employed and 50% earn over £50k. Moreover, 80% use Mumsnet for product advice.

Anecdotal evidence of its huge influence is best exemplifed by one Mumsnetter's recommendation of Waitrose's "Bottom Butter" baby cream as a great anti-wrinkle treamtent. It led to the £2.49 tubs selling out in the supermarket chain and later reappearing on eBay for £15.

When I asked her about monetising Mumsnet - which started to turn a "modest" profit three years ago - Roberts conceded that it was a difficult balance to strike.

"We've had to tread very carefully and not be too commercial because we don't want to alienate out audience ... first and foremost we want to grow a big community, not make a shed load of money," she explained.

Justine Roberts discusses the monetisation of Mumsnet (1:46)

The commercial formula Mumsnet has decided upon involves a combination of discounted product offers from partner companies on which it receives a commission, together with offering access to its members for focus group research. What it's shied away from is traditional advertising.

But avoiding audience alientation through overt commercialism is just one of the rules of engagement she offered for running successful online communities.

Justine Roberts discusses rules of engagement for online communities (1:17)

Equally important, she advised, is to listen and respond to your community, and be transparent and authentic in everything you do.

"We have an enormous and smart focus group that we use all the time," Roberts told the AOP meeting.

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